Comprehensive Review Flashcards
What adverse effects are associated with the use of aminoglycosides?
a. Nephrotoxicity-
b. Ototoxicity
c. Neurotoxicity-
With Nephrotoxicity with aminoglycosides there is
decreased creatinine clearance, casts in urine (chunks of glomerulus), decreased specific gravity, oliguria, proteinuria
With ototoxicity with aminoglycosides there is
directly r/t duration > 10 days & concurrent administration of ototoxic drugs
With neurotoxicity with aminoglycosides there is
skeletal muscle weakness, inhibits pre-junctional release of Ach & decreased postsynaptic sensitivity to Ach- potentiates NMB. *Caution with Parkinson & Myasthenia
Gravis, IV Ca+ can counteract
Examples of Aminoglycosides are
Amikacin, Gentamicin, Neomycin Streptomycin, &
Tobramycin
What is common adverse reaction associated with the use of Tetracyclines? (Doxycycline, Minocycline, Demeclomycin)
a. Photosensitivity
b. Vestibular symptoms with MINOCYCLINE
c. Deposition in teeth in pediatrics (stains teeth permanently)
Vestibular symptoms associated with
minocycline
What is the recommended time of administration of cefazolin (1st Gen) for prevention of post-op
infections?
a. Give pre-op in OR before induction, no sooner than 1 hour prior to procedure
b. Infuse over 3-5 min
c. <120 kg = 2 g IV, >120 kg = 3 g IV
What is the percentage of cross reactivity between penicillins and cephalosporins?
a. Approximately 5%
What may result if vancomycin is infused too fast?
a. Red Neck or Redman Syndrome
b. Clinical signs/symptoms- Histamine release (Non-Immune mediated *Barash) & hypotension
What can prevent red neck redman syndrome with vanco
*Give over 60 minutes to reduce this phenomenon
What NMB can Vancomycin potentiate?
a. Succinylcholine
Adverse reactions of Vancomycin?
a. Nephrotoxicity
b. Ototoxicity (would be at a disadvantage if we added this with an aminoglycoside)
c. Allergic Reactions
What antibiotics are classified as beta-lactams?
PCN, Cephalosporins, Imipenem/ Cilastin, Meropenem, Aztreonam is a monobactam, Carbapenems
Which antibiotics are associated with prolongation of neuromuscular blockade?
Aminoglycosides, Polymyxin B
What antibiotics are associated with prolongation of the QTc interval?
Macrolides (Erythromycin, Clarithromycin, Azithromycin), Vorconazole (antifungal)
- What antibiotic can be used if patient has an allergy to penicillin and cephalosporin?
a. Aztreonam (only gram -)
What are some adverse reactions of Cephalosporins?
BPHRH
a. Bleeding (prolonged PT)
b. Hypersensitivity
c. Pseudomembranous colitis
d. Renal Impairment
e. Hepatic Impairment with Cefoperazone
What is an adverse reaction of Chloramphenicol?
a. Aplastic Anemia
Use of Chloremphenical is
Use is limited to Typhoid Fever & Salmonellosis (if alternatives are less effective)
Define zero order kinetics.
A fixed/constant amount of drug is eliminated/unit of time
Define Hoffman degradation.
Spontaneous degradation via temperature & pH (Acidosis & Cold prolongs)
- What drugs undergo zero order kinetics?
a. ETOH, ASA, phenytoin, heparin, warfarin, acetaminophen
Define first order kinetics?
a. A percentage (%) or fraction of drug is eliminated/unit of time
Define half-life.
a. Time it takes for plasma concentration to fall by half
How are clearance, VD and half-life related?
Half-life is directly related to Vd and inversely related to clearance
Large volume of distribution =
long half-life
Increase in clearance =
Decrease in half-life
What opioids are most effective for the treatment of post-op shivering?
a. Meperidine (via Kappa), butorphanol (Stadol),
Clonidine as far as shivering
effective than meperidine
Which narcotic agonist have the shortest effect site equilibration time?
a. Alfentanil (1.4 min), Remifentanil (1.1)
What are common adverse effects associated with the use of narcotics?
Respiratory depression, N/V, urinary retention, pruritus
Can exacerbate CO2 narcosis
Opiods
Which opioid agent can blunt the adrenal response to stress?
Fentanyl
- How are opioid receptors classified?
a. Mu1 (supraspinal & spinal)-
c. Delta (supraspinal & spinal)- antidepressant effects, physical dependence, vent depression,
constipation (minimal), urinary retention, modulates Mu receptor activity. Agonist- enkephalins,
no delta selective agents. Antagonists- naloxone.
d. Kappa (supraspinal & spinal)- analgesia, sedation, dysphoria, low abuse potential, miosis,
diuresis.
produces analgesia, euphoria, decreased abuse potential, miosis, urinary retention, hypothermia. Agonists- endorphins, morphine, synthetic opioids. Antagonistnaloxone
Mu2 (spinal only)-
analgesia, hypoventilation, physical dependence physical dependence. Agonists- endorphins, morphine, synthetic opioids.
Constipation (marked),
Mu 2
Dysphoria and Diuresis with
Kappa
Mu 2 agonists
Endorphins, morphine, synthetic opioids.
OPIOID AGONIST-ANTAGONISTS principally work here. A
Kappa
Agonists-
Dynorphins (inhibit NT release via type N Ca++ channel causing analgesia, decreased resp. depression, may cause diuresis & dysphoria, increased intensity antagonist- naloxone.
Painful simulation may be resistant to analgesic effects of
kappa receptors,
Low abuse potential which receptors
Kappa
Constipation (minimal)
Delta
Antidepressant effects,
Delta (supraspinal & spinal)-
Physical dependence
Mu2
Which induction agent is associated with increases in ICP?
Ketamine
Which induction agent can blunt the adrenal response to stress?
Etomidate
Caution in adrenal insufficiency patient’s
Etomidate
Which induction agents possess analgesic properties?
Ketamine
- What is the mechanisms of action of:
Etomidate-
e.
binds GABA, enhances affinity of GABA receptor
What is the mechanisms of action of Propofol?-
activates GABA, increases Cl ions- hyperpolarizes cell, functional inhibition, decreases rate of GABA dissociation
What is the mechanisms of action of Dexmedetomidine-
Central alpha-2 agonist (Can cause bradycardia and hypotension)
What is the mechanisms of action of Ketamine
Non-competitive NMDA antagonist, weak GABA actions?, interacts with mu, delta, kappa receptors, muscarinic antagonist, K and Ca channels
What is the mechanisms of action of benzo
Benzodiazepines- different from barbs- enhance affinity of GABA receptor for GABA, by binding/
The benzos increase the
frequency of GABA-mediated ion channel opening and increase Cl permeability and thus cause cellular hyperpolarization and inhibition of neuronal firing
Barbiturates-
Binds to GABA-A receptor at barb binding site and increases GABA mediated Cl influx- hyperpolarizes
cell membrane
Decreases dissociation of GABA, increases duration of GABA activation,
Barbiturates
Depresses RAS, depresses SNS transmission, decreases sensitivity of Ach receptors.
Barbiturates
Can cause bradycardia and hypotension
Dexmedetomidine
What induction agent has most stable cardiovascular profile?
Etomidate
What induction agent increase BP, and cardiac output?
Ketamine
Explain the physiological response to the release of thromboxane and prostacyclin?
a. TXA2- platelet aggregation and vasoconstriction
b. Prostacyclin- inhibits platelet aggregation & vasodilates
c. these 2 work in a balance, if one is opposed, then the other can exert it’s intrinsic properties
What agent can be used to prevent ductus arteriosus closure (Keeps the PDA patent/open)?
a. Alprostadil (Prostin VR, Muse, PGE1)
b. Alprostadil can also give men boners (tx erectile dysfunction if the old lady isn’t doing it for us
anymore…)
Where can we see the use of Alprostadial?
a. Neonatal congenital heart defects
i. Cyanotic PPTT: Pulmonary atresia, pulmonary stenosis, tricuspid atresia, Tetralogy Of Fallot
ii. Acyanotic: Coarctation of aorta, hypoplastic LV (CH)
What agent can be used to close ductus arteriosis?
Indomethacin
- What effects will each prostaglandin have on SVR?
Prostacyclin (PGI2) Epoprostenal *Flolan – *
Decrease SVR, Increase PVR, Decrease Platelet
Aggregation
Epoprostenal *Flolan Treatment of
Primary Pulmonary HTN
What effects will each prostaglandin have on SVR? Alprostadil (PGE1)
Decrease SVR, Increases PVR, Decreases Platelet Aggregation, & Increase Uterine Tone *Keeps PFO open
What effects will each prostaglandin have on SVR? Iloporost (Nebulizer) –
Decrease SVR, Decrease PVR, Decrease Platelet Aggregation
Prostaglandins use as a nebulizer
Iloporost
What effects will each prostaglandin have on SVR? Thromboxane (TXA2)
Thromboxane (TXA2) – Increase SVR, Increases PVR, & Increases Platelet aggregation
What effects will each prostaglandin have on SVR? Dinoprost (PGF2)
Increase or Decrease SVR, Increase PVR, Increase Uterine Tone
Increases Uterine Tone ONLY
Dinoprostone (PGE2) –
3 agents used Increase uterine tone
Alprostadil
Dinoprost
Dinoprotone
What prostaglandin can be used to treat refractory post-partum bleeding? What is the dose?
Carboprost (Hemabate) a PGF-2α that produces uterine contractions? Dose = 250 mcg IM, repeat 1.5-3.5 min intervals
Carboprost Risks of this agent-
vomiting, diarrhea, hyperthermia
What are some characteristics of Prostaglandins?
a. Acidic lipids with great pharmacologic activities
b. Act as local hormones
c. Synthesized from arachidonic acid, dihydrolinoleic acid, & eicosapentaenoic acid
What causes the release of Arachidonic Acid?
Phospholipase C and A2
What drugs can we give to inhibit Phospholipase production inhibiting the Arachidonic acid pathway?
Corticosteroids
What is the half-time of Thromboxane A2?
30 seconds (shorter)
What is the half- time of Prostacyclin?
3 minutes (longer)
What component of prostaglandin synthesis has Several 1000x MORE POTENT bronchial smoothmuscle vasoconstriction than Histamine?
a. Leukotrienes *Therefore it is important to not give asthmatic patients high dose of aspirin or NSAIDs because you can push the phospholipase pathway down the lipoxygenase path producing more leukotrienes
All opioids antagonists
Narcan
What can NSAIDs do to the kidneys?
a. Inhibit cyclooxygenase, interfering with renal prostaglandins
b. Catecholamine induced renal vasoconstriction
What agents are used for cervical ripening prior to labor induction?
a. Dinoprostone; Cervidil, Prostin E2, Prepidil
b. Can be used during weeks 12-28 to evacuate the uterus after missed abortion or intrauterine fetal
death
What enzymes play a role in each step of prostaglandin synthesis?
a. Phospholipase A2 → Arachidonic Acid
i. Cyclooxygenase → Endoperoxides→
1. Thromboxane Synthetase→ Thromboxane (vasoconstriction & platelet agg.)
2. Prostacyclin Synthetase→ Prostacyclin (vasodilator & inhibits platelet agg.)
ii. Lipoxygenase → 5-hydroxyarachidonic acid→ Leukotrienes (1000x more potent
bronchoconstriction than Histamine)
4What is the mechanism of action of:Cromolyn:
Inhibits antigen-induced release of histamine and other autocoids (leukotrienes from
pulmonary mast cells, and other tissue mast cells). basophils.
Does Cromolyn prevent release of histamine form
NO
Does Cromolyn relax bronchial or vascular smooth muscle
No
What is the mechanism of action of antihistamines?
competitive antagonists- occupy receptors on effector cell membranes
Which H2 antagonist is associated with greatest risk of CYP-450 enzyme inhibition? What can it lead to ?
a. Cimetidine
b. Increases plasma concentration of Propranolol, Diazepam, & Lidocaine (all have hepatic extraction ratios & depend on microenzyme metabolism)